Display screen or portion thereof with a graphical user interface



FIG. 1 is a front view of a display screen or portion thereof with a graphical user interface showing a first image of our new design;

FIG. 2 is a front view of a second image thereof;

FIG. 3 is a front view of a third image thereof; and,

FIG. 4 is a front view of a fourth image thereof.

The outermost dash-dot broken line illustrates a display screen or portion thereof, and form no part of the claimed design. The broken line showings of the text, symbols, and images in Figures are included for the purpose of illustrating portions of the display screen with a graphic user interface. The broken lines form no part of the claimed design.

The appearance of the images sequentially transitions between the images shown in FIGS. 1-4. The process, sequence, or period in which one image transitions to another forms no part of the claimed design. 

CLAIM We claim the ornamental design for a display screen or portion thereof with a graphical user interface, as shown and described. 